1. Field of the Invention
The present invention is directed to an improved apparatus and method for collecting a uniform layer of cells from body fluids suitable for use in improved cytological protocols.
2. Description of the Related Art
In a wide variety of technologies, the ability and/or facility in separating matter, typically particulate matter, from a fluid is a critical component in the ability to test for the presence of substances in the fluid. Too often, interference associated with sample preparation obscures the target cells to such a degree that the process is not sufficiently reliable, or too costly. Reducing interference is frequently a function of adequately separating and dispersing mucoid clumps and cell aggregates.
A similar scenario applies to many other fields which involve detection and/or diagnosis, including environmental testing, radiation research, cancer screening, cytological examination, microbiological testing, and hazardous waste contamination, to name just a few.
All that is required for a cytological examination of a sample is that a sample of cells be obtained from the patient, which can typically be done by scraping or swabbing an area, as in the case of cervical samples, or by collecting body fluids, such as those obtained from the chest cavity, bladder, or spinal canal, or by fine needle aspiration. In a conventional manual cytological examination, the cells in the fluid are then transferred onto a glass slide for viewing. In a conventional automated cytological examination, a filter assembly is placed in the liquid suspension and the filter assembly both disperses the cells and captures the cell on the filter, and the filter is removed and placed in contact with a microscope slide.
In all of these endeavors, a limiting factor in the sample preparation protocol is adequately separating solid matter from its fluid carrier (e.g., a variety of fluids, such as physiological, biological and environmental), and in easily and efficiently collecting and concentrating the solid matter in a form readily accessible to microscopic examination. For some types of biological fluid, particularly sputum, various processing steps for breaking mucoid clumps and breaking cell aggregates are designed to evenly distribute cells in the fluid so that microscopic examination of a portion of the fluid will provide a representative sampling of all of the cells in the particulate matter in the fluid.
The prior art contains a number of methods, apparatuses, and structures for dispersing cells in the fluid. For example, U.S. Pat. No. 5,143,627 opens the sample container, inserts a dispersing element into the liquid suspension, and rotates the dispersing element for several minutes. In another example of the prior art, the Saccomanno method is used to process sputum, a process that is time consuming and involves a large number of processing steps. In U.S. Pat. No. 5,471,994, a syringe is used to draw fluid from a sample container through a filter assembly in a housing attached to the cover of the sample container. Mixing of the fluid to disperse particulate material therein is not addressed in this patent.
Prompt processing of urine to obtain fresh cells traditionally has been recommended to ensure the accuracy of quantitative culture results, urinalysis and microscopy. Fresh cells tend to stick to a glass slide much better than cells from preserved urine, allowing for smoother cell spread onto the glass body. Delays in processing, negligent care in either inpatient or outpatient settings and lack of refrigeration may lead to non-optimal slide preparation. One known solution to the delay problem is the use of chemical preservatives with the urine. The presence of liquid preservatives, however, in the urine specimen raises the specific gravity of the specimen to unmeasurable levels and may limit the potential usefulness of the urine for various types of traditional quantitative analysis, such as slide microscopy.
A number of urine or other biological fluid specimen containers have been developed to allow liquid biological specimens to be tested without removing the lid of the urine or biological fluid container. None of the prior art solves the problem of transferring cells in a uniform layer to a slide for examination while at the same time preserving the fluid from which the cells were taken.
Currently, body fluid samples are collected for cytological examinations using special containers. These containers usually contain a preservative solution for preserving the cytology specimen during shipment from the collection site to the cytology laboratory. Furthermore, cytology specimens collected from the body cavities using a swab, smear, flush or brush are also preserved in special containers with fixatives (e.g., alcohol or acetone fixatives) prior to transferring cells onto the slide or membrane for staining or examination.
Diagnostic microbiology and/or cytology, particularly in the area of clinical pathology, bases diagnoses on a microscopic examination of cells and other microscopic analyses. The accuracy of the diagnosis and the preparation of optimally interpretable specimens typically depends upon adequate sample preparation. New methodologies such as immunocytochemistry and image analysis require preparations that are reproducible, fast, biohazard-free and inexpensive. Different cell preparation techniques of the present invention address the issues of non-uniform cell densities, uneven cell distribution and air drying artifact. These preparations have resulted in an even distribution of cells that have superior morphology, which has improved light microscopic visualization and has allowed for the use of image cytometry instruments.
The solid matter preparation techniques of the present invention address the issues of non-uniform matter densities, uneven matter distribution, and sample loss due to the number of steps involved in the sample preparation. The preparations of the present invention result in an even distribution of solids that have superior morphology, improved visualization, and are readily positioned and available for light absorbency analysis without the need to further manipulate or prepare the sample.
The present invention relates to use of an apparatus for collecting matter for detection, analysis, quantification, and/or visualization, and is particularly suitable for separating matter from biological, physiological, and environmental fluids and presenting the particulate matter in an improved manner for cytological examination. The present invention is particularly suited to processing sputum or other high mucous content fluids.
The present invention relates to use of an apparatus that includes structures for engaging a portion of the cover of a collection container, and one or more structures for rotating the collection container. The apparatus may be configured to process a single sample container or more than one, and may be operated manually, semi-automatically, or automatically.
In some embodiments of the invention, the cover may include an outer stationary cover and an inner rotatable cover. In a preferred embodiment of the invention, the inner and outer covers are not rotatable with respect to each other in a first position, and are freely rotatable with respect to each other in a second position.
An apparatus used in the present invention includes a structure or element for rotating a sample container and another structure or element for engaging a portion of the sample container, e.g., a portion of the cover, and holding the portion in place.
The present invention relates to use of an apparatus for collecting a uniform layer of cells from urine or other biological fluid specimen in a cytology collection apparatus or assay module, which can be removably detached from a collection container for application to a slide. The patient or medical person handling the collection may seal the separate container. The collection of the cells in the cytology collection apparatus allows a uniform cell slide to be obtained without contamination of the cells by preservatives, workers or outside materials. The transfer from collection container to the cytology collection apparatus may be carried out without pouring or pipetting the collected specimen. Preferably, once the sample has been collected, the devices do not need to be opened in order to separate the particulate matter from the fluid. That is, an apparatus may be a closed system, and particulate matter may be collected using a closed system.
The present invention is directed to use of a cell collection and distribution apparatus that is preferably closed from the time the sample is collected to the time that particulate matter is captured on a collection site. Once the sample is processed, i.e., the sample is collected, particulate matter in the fluid is dispersed, and particulate matter in the fluid is separated from the fluid by collecting it on a collection site, the apparatus is preferably capable of being disassembled to allow face to face transfer of cells from the device to a slide for microscope examination. The present invention provides an improved method for collecting a monolayer of cells that can be transferred to a microscope slide.
The devices involved in the present invention obviate the need for a trained technician to properly prepare a sample substrate. Thus, time, expense, and expertise are eliminated or reduced as critical factors in sample preparation protocols.
The present invention also provides advantages in sample preparation because it is suitable for use with fresh, untreated cells, unmodified cells, and is particularly designed to provide a thin, uniform layer of solid matter (up to approximately 40 microns or more). This invention is particularly useful in gynecological processes, e.g., for collecting cells for a pap smear, and for processing fluids such as sputum that have mucous clumps in the fluid.
The method of the present invention may involve use of a cytology collection and testing kit containing the cytology collection apparatus described above. The cytology collection kit may also include replacement filters, replacement disposables, and/or other components or solutions typically used during cytological examinations.
The present invention has many advantages for conventional microbiology and hematology. The collected cells are in a predetermined area, and for some embodiment of the invention, are easily accessible to a radiant light source and to a wavelength absorbency meter. Because cells are concentrated in a single layer, they are almost always in one focal plane, thus eliminating or reducing interference by other particles and virtually eliminating technician time and expertise-in establishing a proper reading. The minimal matter overlap achieved ensures that all matter can be easily examined with little chance for critical solids to be obscured by clumps of overlapping solids or debris. The involved apparatuses even permit the use of automated devices to detect and analyze any solid matter in a given population. It also permits a detailed analysis of the chemical composition of the matter.
Further, providing a container cover that has a portion that is rotatable permits particulate matter stirring or dispersion without inserting a stirring mechanism into the sample, thus eliminating a source of contamination that plaques devices that are presently commercially available.
The accompanying drawings show illustrative embodiments of the invention from which these and other of the objectives, novel features and advantages will be readily apparent.